In June 2012, Boring, Ore., (population: about 8,000) and Dull (population 80) in the Perthshire area of Scotland became "A Pair for the Ages" in recognition of their humdrum names and shared hopes of increased cultural and commercial attention.

"People were suddenly interested in visiting our communities. They found out that there's nothing dull and boring about Boring and Dull," Norm Rice, a member of the Boring Community Planning Organization, told CNBC.

Since the hookup became public, Boring businesses, such as the Not So Boring Bar & Grill, have seen more out-of-town visitors and sales of Boring and Dull mugs, T-shirts and other merchandise have generated about $5,000 for Boring projects. There's even a Boring & Dull Day, celebrated on Aug. 9.

In Scotland, "the 'Dull Paired with Boring' sign is now a sightseeing activity along with the likes of Edinburgh Castle and Loch Ness," Dull resident James Pringle said via email.

"We heard about it and thought it would be even better if it became Bland, Dull and Boring," Neil Pokoney, the mayor of Bland Shire (population 6,000) in Australia, told The Scotsman.

Not wanting to mess with what Rice terms "a special relationship," and suspecting that other civic suitors with unusual names might come calling, Boring decided to stay officially "paired" with Dull and to offer Bland something different: membership in the new League of Extraordinary Communities. The Bland Shire Council said yes.

The mundanely named towns may reap some of the same tourism, trade and business benefits enjoyed by the 522 U.S. communities involved in formal international partnerships as part of Sister Cities International, Sister Cities spokeswoman Megha Swamy said.

The next step: Dull & Boring will have to figure out how to update their relationship status on Facebook now that they're in a threesome with Bland.